I hope I will not go off-topic with these questions in mind... Why is that only the Americans and the British have developed and produced VTOL warplanes in mass production like the Harriers, Ospreys and F-35s but the Russians did not push through with their own while other countries did not thought of developing their own version? Didn't they thought about the benefits of having warplanes with such capabilities?
I admire this aircraft technology because it will really save a lot of runways both on land and on carriers (ships). In a archipelago country like my own - the Philippines, having a VTOL warplane like the Harrier will be a great advantage because these warplanes can easily do "island hopping" and literally can be assigned anywhere just like the Marines!
VTOL (plus supersonic and stealth technology) will be the future of air forces.
OT: If you will watch Sci-Fi movies like Star Wars, you will see that spaceships uses VTOL technology in full extent because there are no runways in space and most planets' surfaces are cratered.
More than anything, I think it's a matter of assessing whether the benefits outweigh the drawbacks. STOVL aircraft are often more complex than conventional take off and landing (CTOL) aircraft, with associated maintenance requirements. Additionally, up until now their performance has suffered compared to an equivalent CTOL aircraft (look at the Harrier's performance characteristics compared to CTOL aircraft of the same generation), and even with the F-35B looking like it will greatly improve these characteristics, even it is still going to be less capable than a CTOL Lightning in terms of fuel capacity and its ability to carry certain weapons (at least I believe this is still the case - its weapons bay isn't as large as the CTOL version, please correct if I'm mistaken).
What has to be considered is whether VTOL/STOVL is necessary to the capability an air force wishes to develop. In your example, with say, Harriers deploying "island hopping" style in the Phillipines - it sounds good in theory, but then you have to develop and spread out your infrastructure wherever you wish to deploy them. You have to have sufficient fuel and munitions stocks (and fast jets go through a LOT of fuel) so they can be used effectively, which means not only do the jets have to island-hop, but their whole supply chain has to, as well. So how do you make that process fast enough that the STOVL capability becomes an advantage? Remember you'll need a developed, complicated supply chain, with all its own associated costs and requirements. Or do you have stocks of fuel and munitions ready and waiting at all areas out of which jets are likely to operate? If this is the case you're going to need protected storage for both fuel and munitions, and maintenance infrastructure for the weapons. In addition this means you have to split your warstocks over a wide range of bases, so that will have a flow-on effect if your jets are operating heavily out of a single island and your warstocks are widely distributed. If you need to redistribute them in a hurry, once again, your supply chain will need to be developed. Or would it be of greater advantage (and much simpler) to consolidate your deployment area and invest in jets with a longer range?
Not saying I have the answers, just these questions are relevant to the sort of deployments you're talking about. And I could be wrong about all of it, I'm just speaking theoretically - there are other, more qualified posters here who could give you a better idea of the relative merits of STOVL deployments.
